Ocean currents control the climate around the world. When they suddenly stop, it unleashes an endless cascade of weather disasters including blizzards, superstorms, drought and rapid sea level rise.
They form natural boundaries, dictate how we spread around the planet, create natural defenses, and control our weather. From the World War that began with a gunshot in the Balkans to the feuds of the Appalachians, mountains have also been flashpoints.
Iain travels into the stratosphere in a Cold War fighter, gets his eyebrows singed in Siberia and discovers why Argentina is one of the stormiest places on Earth. All to show why our atmosphere is unique and utterly crucial for life.